Hello, I have a PC microphone, bought at pc components store, which I wanted to use on my RE-Erno 904 NF and on my Elmo ST-600 D M 2-track (both have a 3,5 mm jack connector for mic) but it does not work.
I don't understand about electronics problems, why does it happen?
And what microphone should I buy to use it on the two machines? Only a "vintage" microphone?

P.S. I tried a Philips EL3797/50 mic with Din 5 pin/Din 3 pin---->3,5mm jack adapter, it does not work either; on both, on editor viewer and on projector.

I’m not an electronics expert, but I think you need to use a microphone that matches the type of input on the equipment. Both machines are now quite old, and I’m sure would be designed to use mics of a fairly simple type. Have a look at the manuals for editor and projector. They should give the impedance figure which should be matched with the mic. The other thing that has, I believe, changed is that modern mics can be powered via the input connection. You most likely need one that doesn’t require to be powered, other than by the physical movement caused by sound waves. The kind of thing that should work is the sort of microphone you used to find supplied with portable cassette players. I hope this helps.
Alex

Thank you, alexmuir.
The microphone for pc that I have, I don't know how it is powered, it does not have a USB port (for powered by Pc) or a battery.
Also as ohms is different, on the packaging shows a different impedance from viewer and projector.
I had an old shotgun that could works, but I can't find it anymore. I have to get a cassette recorder microphone or of an old projector, or an old shotgun for film cameras (like Fuji, Elmo, etc.).